Novel sulfonated poly (ether ether ketone)/silica coated carbon nanotubes high‐performance composite membranes for direct methanol fuel cell

Abstract

The major risk of using carbon nanotubes (CNTs) to modify proton exchange membranes (PEMs) in fuel cells is possible short-circuiting due to the excellent electrical conductivity of CNTs. In this article, silica-coated CNTs (SiO 2 @CNTs) were successfully prepared by a simple sol-gel process and then used as a new additive in the preparation of sulfonated poly (ether ether ketone) (SPEEK)-based composite membranes. The insulated and hydrophilic silica coated on the surface of CNTs not only eliminated the risk of short-circuiting, but also enhanced the interfacial interaction between CNTs and SPEEK, and hence promoted the homogeneous dispersion of CNTs in the SPEEK matrix. Moreover, compared to the methanol permeability of the pure SPEEK membrane (3.42 × 10 À7 cm 2 s À1 ), the SPEEK/SiO 2 @CNT composite membrane with a SiO 2 @CNT loading of 5 wt% exhibits almost one order of magnitude decrease of methanol crossover, while the proton conductivity still remained above 10 À2 S cm À1 at room temperature. The obtained results expose the possibility of SPEEK/SiO 2 @CNT membranes to be served as highperformance PEMs in direct methanol fuel cells.

Proton Conductivity of Composite Polyelectrolyte Membranes with Metal‐Organic Frameworks for Fuel Cell Applications

“…As an example, inorganic fillers have been also added in order to improve the mechanical and hydrolytic properties of SPEEK membranes, while only slightly altering their proton conductivity and permeability properties. Similarly to Nafion, a wide variety of fillers have been used to improve thermal stability, mechanical properties and proton conductivity of SPEEK membranes, including silica, perovskite oxides, graphene oxide, and carbon nanotubes …”

Amelioration in physicochemical properties and single cell performance of sulfonated poly(ether ether ketone) block copolymer composite membrane using sulfonated carbon nanotubes for intermediate humidity fuel cells

“…Cui et al prepared CNTs coated with silica as an additive to SPEEK‐based membranes. The hydrophilic, insulated silica on CNTs prevented short circuit in the membrane and facilitated efficient dispersion of the filler into the polymer matrix through the interfacial interactions which resulted to good physiochemical properties . Herein, we synthesized a sulfonated diblock copolymer (SDBC) made up of SPEEK and partially fluorinated poly(arylene ether sulfone) (PAES) and fabricated an organic‐inorganic hybrid membrane using SCNT as the inorganic additive.…”

Effect of Graphene Oxide on the Characteristics of sPEEK-Chitosan Membranes for Direct Methanol Fuel Cells

“…Several membranes of hydrocarbons have been developed, including polyether sulfone, polyether ketone, and acrylonitrile butadiene styrene (ABS) [3]. Ketone polyether ethers have relatively high proton conductivity, good thermochemical properties and low cost [4]. sPEEK can be applied to fuel cells but must be modified with sulfonation to be hydrophilic.…”